Chuck



Patented Sept. 29, 1942 l UNITED STATES PATENTA .OFFICE 2,297,140` fw Y'y Y cHUcK Henry O. Fossum, Detroit, Mich., assignor to' ChicagoPneumatic Tool Company, New York, N. Y., a corporation of New vJerseyApplication october 29, 1940, serial No. 363,239

2 Claims.

This invention relates generally to chuck mechanism and particularly toa chuck assembly adapted for use in diamond drills and like machines.More specifically, the invention is concerned with a rotary drivingchuck of the vtype having radially reciprocable jaws and a set screwmechanism for moving the jaws into gripping engagement with the driventool.

One object of the invention is to enable the set screws to controlmovementof the chuck jaws from gripping position through the pro- Visionof spring means urging the jaws outward into engagement with the screws.

Another object of the invention is to place the set screw mechanismwholly within the periphery of the chuck assembly, and obtain thereby abalanced chuck free of radial projections.

Another object of the invention is to prolong the useful life of thechuck assembly by providing therein a plurality of selectively usableseries of set screw openings.

Other objects and structural details of the inventi-on will be moreapparent from the following description when read in conjunctionA withthe accompanying drawing, wherein:

Fig. l is a view in longitudinal section of a chuck assembly embodyingthe invention, showing the manner in which the assembly acts to connectthe feed screw and drilling rod of a diamond drill;

Fig. 2 is a view, partly in cross section and partly in front elevation,of the chuck assembly shown in Fig. 1, and is taken substantially alongthe irregular line 2 2 of Fig. 1;

Fig. 3 is a View, partly in elevation and partly in section, of thechuck body on a reduced scale; and

Fig. 4 is a fragmentary detail view, in perspective, of one of the chuckjaws.

The invention is disclosed herein as embodied in a chuck for use indiamond drills. Such a drill includes, as shown in Fig. 1, a projectingfeed screw I through which a working tool in the form of a tubulardrilling rod II is passed.V

The feed screw I0 is given a rotary driving movement during operation ofthe drill and is at the same time advanced toward the work. In orderthat similar movements may be imparted to the drilling rod II, a chuckmechanism is provided which is adjustable to interlock the rod and thefeed screw for operation as a unit.

Thel present chuck mechanism is an assembly and includes a main bodyportion I2 secured to the outer end of the feed screw ID. The chuck CIIbody l2 has a forwardly projecting portion I3 of 55 reduced diameter(see Fig. A3)A and is formedI with a central bore I4 to permit thepassage ofthe drill rod I IA therethrough. Referring alsolto Figs. 2 and3, it will be seen that projecting portion I3 is bifurcated by atransverse longitudinally extending slot I5. Arranged in the slot I5 aretwo oppositely disposed lugsor chuck jaws I which are held in spacedrelation by a pair of spring clips I'I pressed in complementaryl'recesses at the rear and front ends of the jaws. The' chuck jaws I6 arethus caused to rotate with the main chuck body I2 and are movableradially with respect tothe central bore I4 into and out of engagementwith the drilling rodV I I. The rod I I extends between the jaws I6 andwhen gripped thereby is constrained to move with the chuck body and feedscrew I0. The adjacent faces of the chuck jaws I6 are concave in shape(see Fig. 4) to obtain a greater bearing upon the drilling rod and areserrated to assure a rm gripping engagement with the rod.

The means for pressing the jaws I6 into gripping engagement with thedrilling rod I I is cornprised in a housing I8 forming another elementof the chuck assembly. The housing I8 encloses the bifurcated projectingportion I3 and is secured by bolts I9 to an annular flange 2| formed onthe chuck body I2. The drilling rod II eX- tends through a centralopening 22 (Fig. 1) in the housing I8. Formed in the inwardly extendingrim of the housing I8 is a plurality of oppositely disposed pairs ofscrew threaded openings 23. When the housing I8 is bolted to the flange2I, one or another of the pairs of openings 23 is aligned with thetransverse slot I5. A set screw 24 is inserted in each of the selectedaligned openings 23 and extends into the slot I5 to contact a respectiveone of the chuck jaws I6. By adjustment of the set screws 24 within theopenings 23 the jaws I6 may be pressed inward to grip the drilling rod,or the pressure on the jaws may be relaxed and the springs II therebyenabled to move the jaws to inelective position. Each set screw lieswholly within the rim of the housing I8 and is adjusted by a wrenchhaving a polygonal shank insertable into a correspondingly shaped recessWithin the screw. By placing the set screw mechanism within theperiphery of the housing, a better balance of the chuck assembly isobtained. Furthermore the safety of operation is increased throughelimination of potentially injurious radial projections.

An important feature of the invention is the provision of a plurality ofpairs of openings 23. In the operation of a diamond drill it isnecessary suitable for use, the housing I8 may be readjusted withrespect to the body portion I2 to bring rim of said housing.

a new set of openings into registryrwiththeajaws' I6. The several pairsof Jopenings-arefsoar ranged that in any rotative position of'thehousingin which the bolts I9 mayfbev inserteddn the rim thereof one or anotherof the pairs of openings will be aligned with the transverseslotl5.

What is claimed is:

1. vA chuck assembly, `comprising-a 'rotatable chuck-body having alongitudinalbore .through which a-drilling or like tool may be passed,fapair of radially movable chuck jaws within said chuck bodyior grippingthe tool,'a housing partly en.

closing said chuckbody and having anannular rim parallelingsaidlongitudinal bore, a plural- -ity of oppositely disposed pairs. ofscrew threaded transverse openings inthe rim of said housing,

means for securing saidhousing'in a plurality of positions relatively tosaid chuck body to bring said pairs of openings selectivelyinto aposition exposing said chuck jaws, -said means including 2. A chuckassembly, comprising a rotatable Nchuck body having a longitudinal borethrough "whichi-alrdr'illing ;or.like tool may be passed, a-pair-cffiradiallyrmovable chuck jaws within said :chuck-bodyforgripping the tool, a housing partlytenclosingsaidchuck body andhaving an annular rim paralleling said longitudinal bore and a frontfaceholding said chuck jaws against outward-axial movement, .said .frontface being .closed exceptior an aperture permitting thepassagecf .thedrilling tool therethrough, a plurality of oppositely vdisposed pairs ofscrew threaded 4transverse openings in the rim of said housing, meansVfor securing said housing in aplurality of .positions relatively'tosaid chuck body to bring said pairs of openingsselectively into aposition eXposingsaid chuck.jawsandV set screws adjustable within aselected pair of transverse openings for moving said .chuck jaws intogripping engagement with .the tool.

HENRY O.`FOSSUM.

